Variable muffler

ABSTRACT

A variable muffler may include a housing, a plurality of chambers formed by partitions in the housing, an inlet pipe connected to at least a chamber for flowing exhaust gas into the housing, an outlet pipe connected to at least a chamber for discharging the exhaust gas having flowed into the housing to the exterior, an inner pipe for directly communicating between at least two chambers in the housing so that the exhaust gas of the inlet pipe is communicated to the outlet pipe therethrough, and a variable valve that is disposed downstream of the inner pipe and of which opening amount is continuously adjusted according to pressure of exhaust gas passing through the inner pipe.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2009-0118713 filed in the Korean Intellectual Property Office on Dec. 2, 2009, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a variable muffler, more particularly to a variable muffler including a valve capable of controlling a flow rate of exhaust gas in two stages.

2. Description of Related Art

Generally, as to gasoline engines applied to vehicles, silence is required at a normal engine speed range, for example at a range of 750 rpm to 2500-3000 rpm, and high output power rather than the silence is required at a high speed range, for example at more than 3000 rpm.

The engine noise is generated by exhaust noise from the engine. To reduce the noise and to generate high output power, various mufflers have been disclosed.

To satisfy the requirement, as conventional fashion, a muffler including a variable valve that is mounted inside a muffler and reduces exhaust gas pressure has been disclosed.

The muffler is mounted such that a variable valve disposed at an outlet of exhaust gas of a communicated pipe in the muffler is supported by an elastic member.

Herein, at a normal speed of the engine, because exhaust gas pressure is low, the variable valve is in a state of being closed by elastic force exerted on the variable valve toward a communicating pipe of the elastic member that is higher than the exhaust gas pressure, and exhaust discharged from the muffler outwardly passes through a passage having exhaust gas resistance and thereby the exhaust noise is reduced.

Meanwhile, when the engine reaches 3000 rpm, in a high speed range, the exhaust gas pressure is increased and the exhaust gas pressure is higher than the supporting force of the elastic member, and thereby the variable valve is opened.

However, the conventional fashion for opening or closing a variable valve simply according to exhaust gas pressure has a limit in which flow noise at a high speed is increased, torque at a low speed is decreased, exhaust gas pressure at a high speed is decreased, and the like.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY OF THE INVENTION

Various aspects of the present invention are directed to provide a variable muffler having advantages of precisely controlling a flow rate of exhaust gas in two stages in order to reduce exhaust gas noise.

In an aspect of the present invention, the variable muffler may include a housing, a plurality of chambers formed by partitions in the housing, an inlet pipe connected to at least a chamber for flowing exhaust gas into the housing, an outlet pipe connected to at least a chamber for discharging the exhaust gas having flowed into the housing to the exterior, an inner pipe for directly communicating between at least two chambers in the housing so that the exhaust gas of the inlet pipe is communicated to the outlet pipe therethrough, and a variable valve that is disposed downstream of the inner pipe and of which opening amount is continuously adjusted according to pressure of exhaust gas passing through the inner pipe.

The variable valve may include a valve body connected to the inner pipe and a plurality of valves hingedly and elastically connected each other sequentially, wherein a first valves of the valves is hingedly and elastically connected to the valve body.

The variable valve may include the valve body connected to the inner pipe, a first hinge portion disposed to the valve body, the first valve hingedly connected to the first hinge portion, a second hinge portion disposed to the first valve, and a second valve hingedly connected to the second hinge portion.

The variable valve may further include a first elastic member which is disposed to the first hinge portion and elastically biases the first valve in a direction, and a second elastic member which is disposed to the second hinge portion and elastically biases the second valve in the direction, wherein an elastic coefficient of the first elastic member is less than an elastic coefficient of the second elastic member.

The partition may include first and second partitions disposed within the housing, and the first and second partitions and the housing form first, second, and third chambers, wherein the inlet pipe is communicated with the third chamber through the first chamber, the first partition and the second partition.

A first partition penetration hole may be formed to the first partition for communicating the first chamber with the second chamber formed by the first and second partitions, wherein a penetration hole is formed to the outlet pipe for communicating with the second chamber, wherein the second chamber includes a sound absorbent therewithin, and wherein the sound absorbent is made of glass wool material.

The outlet pipe may be formed with a “U” shape, wherein the outlet pipe penetrates the first, second, and third chambers at least once, and wherein the outlet pipe penetrates the first chamber, the second chamber, the third chamber, the second chamber, the first chamber, the second chamber and the third chamber sequentially.

The inner pipe may be disposed between the first chamber and the third chamber for communicating therebetween.

According to the variable muffler of the exemplary embodiment of the present invention, the muffler may control a flow rate of exhaust gas in multiple stages according to engine operation condition, so that exhaust noise may be reduced.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a variable muffler according to an exemplary embodiment of the present invention.

FIG. 2 and FIG. 3 is a perspective view of the variable muffler according to the exemplary embodiment of the present invention.

FIG. 4 is a top plan view of the variable muffler according to an exemplary embodiment of the present invention.

FIG. 5 shows an operating state of the variable muffler at a low speed range according to the exemplary embodiment of the present invention.

FIG. 6 shows an operating state of the variable muffler at a middle speed range according to the exemplary embodiment of the present invention.

FIG. 7 shows an operating state of the variable muffler at a high speed range according to the exemplary embodiment of the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

FIG. 1 is a top plan view of a variable muffler according to an exemplary embodiment of the present invention and FIG. 2 and FIG. 3 is a perspective view of the variable muffler according to the exemplary embodiment of the present invention.

FIG. 4 is a top plan view of the variable muffler according to an exemplary embodiment of the present invention and FIG. 5 shows an operating state of the variable muffler at a low speed range according to the exemplary embodiment of the present invention.

FIG. 6 shows an operating state of the variable muffler at a middle speed range according to the exemplary embodiment of the present invention and FIG. 7 shows an operating state of the variable muffler at a high speed range according to the exemplary embodiment of the present invention.

Referring to FIG. 1 to FIG. 3, a variable muffler according to an exemplary embodiment of the present invention includes a housing 100, an inlet pipe 110, an outlet pipe 120, an inner pipe 130 disposed within the housing 100.

The inside of the housing 100 is divided into a plural of chambers 101, 102, and 103 by partitions 140 including a plurality of holes therein.

One end of the inlet pipe 110 is outwardly protruded from the housing 100, and the other end thereof is formed so that exhaust gas flows into the housing 100.

Further, the inlet pipe 110 is installed in a state of being inserted into the housing 100 so that exhaust gas flowing into the housing 100 is exhausted toward the rear side of the housing 100.

The partition 140 includes a first and second partition 141 and 142 disposed within the housing 100, and the first and second partition 141 and 142 and the housing 100 form a first, second, and third chamber 101, 102, and 103.

The inlet pipe 110 communicates with the third chamber 103 through the first chamber 101, the first partition 141 and the second partition 142.

A penetration hole 123 is formed to the outlet pipe 120 for communicating with the second chamber 102.

The penetration hole 123 may be a plurality of holes formed to an exterior circumference of the outlet pipe 120 to reduce noise.

The second chamber 102 is filled with a sound absorbent 240.

The sound absorbent 240 may be made of glass wool so as to reduce flow noise generated when exhaust gas passes through the second chamber 102.

The inner pipe 130 is disposed to communicate the first chamber 101 with the third chamber 103.

A first partition penetration hole 143 is formed to the first partition 141 to communicate the first chamber 101 with the second chamber 102.

The outlet pipe 120 is formed with a “U” shape.

The outlet pipe 120 may penetrate the first, second, and third chamber 101, 102, and 103 at least once.

The outlet pipe 120 may penetrate the first chamber 101, the second chamber 102, the third chamber 103, the second chamber 102, the first chamber 101, the second chamber 102 and the third chamber 103 sequentially.

A variable valve 200 is disposed to a downstream side of the inner pipe 130, which is the inner pipe exit 132, for controlling stream of exhaust gas.

The variable valve 200, as shown in FIG. 4 to in FIG. 7 includes a valve body 201 connected to the inner pipe exit 132, a first hinge portion 210 disposed to the valve body 201, a first valve 231 hingedly connected to the first hinge portion 210, a second hinge portion 220 disposed to the first valve 231 and a second valve 232 hingedly connected to the second hinge portion 220.

The variable valve 200 further may include a first elastic member 211 which is disposed to the first hinge portion 210 and elastically supports the first valve 231 and a second elastic member 222 which is disposed to the second hinge portion 220 and elastically supports the second valve 232.

An elastic coefficient of the first elastic member 211 is less than an elastic coefficient of the second elastic member 222.

That is, displacement of the first valve 231 elastically supported by the first elastic member 211 is greater than that of the second valve 232 supported by the second elastic member 222.

Herein, the first and second controlling valves 231 and 232 of the variable valve 200 has an area that is capable of opening or closing one end of the inner pipe 130, and it is formed with a circular plate shape.

In this way, an operating state of the variable valve 200 according to engine speed is automatically controlled, so an amount of exhaust gas passing through the chambers 101, 102, and 103 of the housing 100 is controlled. An operating state of the variable valve 200 will hereinafter be described according to an operating state of a low speed, a middle speed, and a high speed.

In the case of a low speed, the variable valve 200 is slightly opened for the exhaust to be leaked out, so that the exhaust gas passing through the inlet pipe 110 flows into the first chamber 101 through the third chamber 103, an inner pipe entrance 131, the inner pipe 130 and the variable valve 200 and exits through the outlet pipe entrance 121.

At the same time, partial exhaust gas passes through the penetration hole 123.

The sound absorbent 240 filled within the second chamber 102 may reduce flow noise.

The partial exhaust gas flows into the first chamber 101 through the first partition penetration hole 143 and then exits through the outlet pipe entrance 121 and the outlet pipe 120.

In this case, pressure of the exhaust gas passing through the inlet pipe 110 is relatively low, so that the variable valve 200, as shown in FIG. 5, is almost closed (slightly opened).

That is, the variable valve 200 is almost closed due to elastic force of the first elastic member 211 elastically supporting the first valve 231.

In the case of a middle speed, the first valve 231 is opened by pressure exerted on the inside of the inlet pipe 110, inlet pipe exit 112, the third chamber 103 and the inner pipe 130 against elastic force of the first elastic member 211.

That is, an angle θ1 defined by the first valve 231 is maintained the same as an angle θ2 defined by the second valve 232.

Therefore, a portion of exhaust gas flowing into the second chamber 102 flows into the first chamber 101 through the first partition penetration hole 143, and the remaining portion flows into the first chamber 103 through the variable valve 200.

The exhaust gas is then discharged out of the housing 100 through the outlet pipe entrance 121.

In the case of a high speed, the first valve 231 and the second valve 232 are opened by pressure exerted on the inside of the inlet pipe 110, inlet pipe exit 112, the third chamber 103 and the inner pipe 130 against elastic force of the first elastic member 211 and the second valve 232.

That is, an angle θ2 defined by the second valve 232 is higher than an angle θ1 defined by the first valve 231.

Particularly, in the case of the high speed the first valve 231 and the second valve 232 are opened simultaneously, exhaust gas flows out more smoothly than in the case of the low speed or in the case of the middle speed, so that engine output may be improved.

Also, resistance generated in the high speed may be suppressed, so that exhaust gas noise may be reduced.

The outlet pipe 120 is relatively formed at length, so that low frequency noise may be reduced effectively.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A variable muffler comprising: a housing; a plurality of chambers formed by partitions in the housing; an inlet pipe connected to at least a chamber for flowing exhaust gas into the housing; an outlet pipe connected to at least a chamber for discharging the exhaust gas having flowed into the housing to the exterior; an inner pipe for directly communicating between at least two chambers in the housing so that the exhaust gas of the inlet pipe is communicated to the outlet pipe therethrough; and a variable valve that is disposed downstream of the inner pipe and of which opening amount is continuously adjusted according to pressure of exhaust gas passing through the inner pipe.
 2. The muffler of claim 1, wherein the variable valve comprises: a valve body connected to the inner pipe and a plurality of valves hingedly and elastically connected each other sequentially, wherein a first valves of the valves is hingedly and elastically connected to the valve body.
 3. The muffler of claim 2, wherein the variable valve comprises: the valve body connected to the inner pipe; a first hinge portion disposed to the valve body; the first valve hingedly connected to the first hinge portion; a second hinge portion disposed to the first valve; and a second valve hingedly connected to the second hinge portion.
 4. The muffler of claim 3, wherein the variable valve further comprises: a first elastic member which is disposed to the first hinge portion and elastically biases the first valve in a direction; and a second elastic member which is disposed to the second hinge portion and elastically biases the second valve in the direction.
 5. The muffler of claim 4, wherein an elastic coefficient of the first elastic member is less than an elastic coefficient of the second elastic member.
 6. The muffler of claim 1, wherein the partition comprises first and second partitions disposed within the housing, and the first and second partitions and the housing form first, second, and third chambers.
 7. The muffler of claim 6, wherein the inlet pipe is communicated with the third chamber through the first chamber, the first partition and the second partition.
 8. The muffler of claim 7, wherein a first partition penetration hole is formed to the first partition for communicating the first chamber with the second chamber formed by the first and second partitions.
 9. The muffler of claim 8, wherein a penetration hole is formed to the outlet pipe for communicating with the second chamber.
 10. The muffler of claim 9, wherein the second chamber includes a sound absorbent therewithin.
 11. The muffler of claim 10, wherein the sound absorbent is made of glass wool material.
 12. The muffler of claim 6, wherein the outlet pipe is formed with a “U” shape.
 13. The muffler of claim 12, wherein the outlet pipe penetrates the first, second, and third chambers at least once.
 14. The muffler of claim 13, wherein the outlet pipe penetrates the first chamber, the second chamber, the third chamber, the second chamber, the first chamber, the second chamber and the third chamber sequentially.
 15. The muffler of claim 6, wherein the inner pipe is disposed between the first chamber and the third chamber for communicating therebetween. 